1. W. Brandt and R. Laubert, Phys. Rev. Letters 24, 1037 (1970).
2. It is questionable whether the concept of diabatic states can be applied to level crossings in which there is a change in angular momentum (o-7, 7–6, etc.) The author is not aware of any such set of diabatic states.
3. J.E. Bayfield, accompanying article, p. 397.
4. D.R. Bates and R.H.G. Reid, in Advances in Atomic and Molecular Physics 4, 13 (1968); D.R. Bates, K. Ledsham and A.L. Stewart, Phil. Trans. Roy. Soc. (Lond) 246, 215 (1953).
5. G.J. Lockwood and E. Everhart, Phys. Rev. 125, 567 (1962).